[u/mrichter/AliRoot.git] / PHOS / AliPHOSv4.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/* $Id$ */

//_________________________________________________________________________
// Implementation of the PHOS manager class for fast simulations     
// Tracks particles until the reach a grossly designed PHOS module
// Modify the particles property (momentum, energy, type) according to
//  the PHOS response function. The result is called a virtual reconstructed
//  particle.                
//
//*-- Author: Yves Schutz (SUBATECH)

// --- ROOT system ---

#include "TBRIK.h"
#include "TNode.h"
#include "TParticle.h"

// --- Standard library ---

#include <stdio.h>

// --- AliRoot header files ---

#include "AliPHOSv4.h"
#include "AliRun.h"
#include "AliConst.h"

ClassImp(AliPHOSv4)

//____________________________________________________________________________
AliPHOSv4::AliPHOSv4(const char *name, const char *title):
  AliPHOS(name,title)
{
  // ctor

  // gets an instance of the geometry parameters class  
   
  fGeom =  AliPHOSGeometry::GetInstance(title, "") ; 

  if (fGeom->IsInitialized() ) 
    cout << "AliPHOS" << Version() << " : PHOS geometry intialized for " << fGeom->GetName() << endl ;
  else
    cout << "AliPHOS" << Version() << " : PHOS geometry initialization failed !" << endl ;   
  
  SetBigBox(0, fGeom->GetOuterBoxSize(0) ) ;
  SetBigBox(1, fGeom->GetOuterBoxSize(1) + fGeom->GetPPSDBoxSize(1) ) ; 
  SetBigBox(2, fGeom->GetOuterBoxSize(0) ); 

  fNRecParticles = 0 ; 
  fFastRecParticles = new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100) ;

  fResPara1 = 0.030 ;    // GeV
  fResPara2 = 0.00003 ; 
  fResPara3 = 0.00001 ; 

  fPosParaA0 = 2.87 ;    // mm
  fPosParaA1 = -0.0975 ;  
  fPosParaB0 = 0.257 ;   
  fPosParaB1 = 0.137 ; 
  fPosParaB2 = 0.00619 ; 
}

//____________________________________________________________________________
AliPHOSv4::~AliPHOSv4()
{
  // dtor
 
  fFastRecParticles->Delete() ; 
  delete fFastRecParticles ;
  fFastRecParticles = 0 ; 

}

//____________________________________________________________________________
void AliPHOSv4::AddRecParticle(const AliPHOSFastRecParticle & rp)
{  
  // Add a virtually reconstructed particle to the list 

  new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
  fNRecParticles++ ; 
}

//____________________________________________________________________________
void AliPHOSv4::BuildGeometry()
{
  // Build the PHOS geometry for the ROOT display
   //BEGIN_HTML
  /*
    <H2>
     PHOS FAST in ALICE displayed by root
    </H2>
    <H4> All Views </H4>
    <P>
    <CENTER>
    <IMG Align=BOTTOM ALT="Fast All Views" SRC="../images/AliPHOSv4AllViews.gif"> 
    </CENTER></P>
    <H4> Front View </H4>
    <P>
    <CENTER>
    <IMG Align=BOTTOM ALT="Fast Front View" SRC="../images/AliPHOSv4FrontView.gif"> 
    </CENTER></P>
  */
  //END_HTML  
 
  const Int_t kColorPHOS = kRed ;
  
  Double_t const kRADDEG = 180.0 / kPI ;
  
  new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2, 
	     GetBigBox(1)/2, 
	     GetBigBox(2)/2 );
  
  // position PHOS into ALICE

  Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
  Int_t number = 988 ; 
  Float_t pphi =  TMath::ATan( GetBigBox(0)  / ( 2.0 * fGeom->GetIPtoCrystalSurface() ) ) ;
  pphi *= kRADDEG ;
  TNode * top = gAlice->GetGeometry()->GetNode("alice") ;
 
  char * nodename = new char[20] ;  
  char * rotname  = new char[20] ; 

  for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) { 
   Float_t angle = pphi * 2 * ( i - fGeom->GetNModules() / 2.0 - 0.5 ) ;
   sprintf(rotname, "%s%d", "rot", number++) ;
   new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0);
   top->cd();
   sprintf(nodename,"%s%d", "Module", i) ;    
   Float_t x =  r * TMath::Sin( angle / kRADDEG ) ;
   Float_t y = -r * TMath::Cos( angle / kRADDEG ) ;
   TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ;
   bigboxnode->SetLineColor(kColorPHOS) ;
   fNodes->Add(bigboxnode) ;
  }
  delete[] nodename ; 
  delete[] rotname ; 
}

//____________________________________________________________________________
void AliPHOSv4::CreateGeometry()
{
  // Create the geometry for GEANT
  
  AliPHOSv4 *phostmp = (AliPHOSv4*)gAlice->GetModule("PHOS") ;
  
  if ( phostmp == NULL ) {
    
    fprintf(stderr, "PHOS detector not found!\n") ;
    return ;
    
  }

  // Get pointer to the array containing media indeces
  Int_t *idtmed = fIdtmed->GetArray() - 699 ;
  
  Float_t bigbox[3] ; 
  bigbox[0] =   GetBigBox(0) / 2.0 ;
  bigbox[1] =   GetBigBox(1) / 2.0 ;
  bigbox[2] =   GetBigBox(2) / 2.0 ;
  
  gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
  
  // --- Position  PHOS mdules in ALICE setup ---
  
  Int_t idrotm[99] ;
  Double_t const kRADDEG = 180.0 / kPI ;
  
  for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
    
    Float_t angle = fGeom->GetPHOSAngle(i) ;
    AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
 
    Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;

    Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
    Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
    gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
 
  } // for GetNModules

}


//____________________________________________________________________________
void AliPHOSv4::Init(void)
{
  // Prints out an information message
  
  Int_t i;

  printf("\n");
  for(i=0;i<35;i++) printf("*");
  printf(" FAST PHOS_INIT ");
  for(i=0;i<35;i++) printf("*");
  printf("\n");

  // Here the PHOS initialisation code (if any!)

  for(i=0;i<80;i++) printf("*");
  printf("\n");
  
}

//___________________________________________________________________________
Float_t AliPHOSv4::GetBigBox(Int_t index)
{
  // Get the X, Y or Z dimension of the box describing a PHOS module
  
  Float_t rv = 0 ; 

  switch (index) {
  case 0:
    rv = fBigBoxX ; 
    break ; 
  case 1:
     rv = fBigBoxY ; 
    break ; 
  case 2:
     rv = fBigBoxZ ; 
    break ; 
 }
  return rv ; 
}

//___________________________________________________________________________
void AliPHOSv4::MakeBranch(Option_t* opt)
{  
  // Create new branch in the current reconstructed Root Tree
 
  AliDetector::MakeBranch(opt) ;
  
  char branchname[10];
  sprintf(branchname,"%s",GetName());
  char *cd = strstr(opt,"R");
  
  if (fFastRecParticles && gAlice->TreeR() && cd) {
    gAlice->TreeR()->Branch(branchname, &fFastRecParticles, fBufferSize);
  }
}

//____________________________________________________________________________
Double_t AliPHOSv4::MakeEnergy(const Double_t energy)
{  
  // Smears the energy according to the energy dependent energy resolution.
  // A gaussian distribution is assumed

  Double_t sigma  = SigmaE(energy) ; 
  return  fRan.Gaus(energy, sigma) ;   
}

//____________________________________________________________________________
TVector3 AliPHOSv4::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const Double_t phi)
{
  // Smears the impact position according to the energy dependent position resolution
  // A gaussian position distribution is assumed

  TVector3 newpos ;
  Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
  Double_t x = fRan.Gaus( pos.X(), sigma ) ;
  sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
  Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
  Double_t y = pos.Y() ; 
  
  newpos.SetX(x) ; 
  newpos.SetY(y) ; 
  newpos.SetZ(z) ; 
	      
  return newpos ; 
}

//____________________________________________________________________________
void AliPHOSv4::MakeRecParticle(const Int_t modid, const TVector3 pos, AliPHOSFastRecParticle & rp)
{
  // Modify the primary particle properties according
  //  1. the response function of PHOS
  //  2. the performance of the EMC+PPSD setup
  
  Int_t type = MakeType( rp ) ;
  rp.SetType(type) ;

  
  // get the detected energy

  TLorentzVector momentum ;  
  rp.Momentum(momentum) ; 
  Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ; 
  Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
  Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)  
					 + TMath::Power( rp.GetMass(), 2) ) ;
 
  // get the angle of incidence 
  
  Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ; 
  Double_t incidencephi   = ( 270 + fGeom->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;   

  // get the detected direction
  
  TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ; 
  modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ; 

  // Set the modified 4-momentum of the reconstructed particle

  rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ; 

 }

//____________________________________________________________________________
Int_t AliPHOSv4::MakeType(AliPHOSFastRecParticle & rp )
{
  // Generate a particle type using the performance of the EMC+PPSD setup

  Int_t rv =   AliPHOSFastRecParticle::kUNDEFINED ;
  Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
  Int_t test ; 
  Float_t ran ; 
  if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) ) 
    test = - 1 ;
  else
    test = rp.GetPdgCode() ; 

  switch (test) { 

  case 22:    // it's a photon
    ran = fRan.Rndm() ; 
    if ( ran <= 0.5 )  // 50 % 
      rv =  AliPHOSFastRecParticle::kGAMMA ; 
    else {
      ran = fRan.Rndm() ; 
      if( ran <= 0.9498 )
	rv =  AliPHOSFastRecParticle::kNEUTRALEM ; 
      else
	rv =  AliPHOSFastRecParticle::kNEUTRALHA ; 
    }     
    break ; 

  case 2112:  // it's a neutron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9998 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHA ; 
    else 
      rv = AliPHOSFastRecParticle::kNEUTRALEM ; 
    break ; 

  case -2112: // it's a anti-neutron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9984 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHA ; 
    else 
      rv =  AliPHOSFastRecParticle::kNEUTRALEM ; 
    break ; 
    
  case 11:    // it's a electron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kELECTRON ; 
    else 
      rv =  AliPHOSFastRecParticle::kCHARGEDHA ; 
    break; 

  case -11:   // it's a positon
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kELECTRON ; 
    else 
      rv =  AliPHOSFastRecParticle::kCHARGEDHA ; 
    break; 

  case -1:    // it's a charged
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kCHARGEDHA ; 
    else 
      rv =  AliPHOSFastRecParticle::kGAMMA ; 

    break ; 
  }
    
  
  return rv ;
}

//___________________________________________________________________________
void AliPHOSv4::ResetPoints()
{
  // This overloads the method in AliDetector
  
  ResetFastRecParticles() ; 
}

//___________________________________________________________________________
void AliPHOSv4::ResetFastRecParticles()
{
  // Resets the list of virtual reconstructed particles
 
  if (fFastRecParticles) 
    fFastRecParticles->Clear() ;
  fNRecParticles = 0 ; 
}

//___________________________________________________________________________
void AliPHOSv4::SetBigBox(Int_t index, Float_t value)
{
  // Set the size of the Box describing a PHOS module
  
  switch (index) {
  case 0:
    fBigBoxX = value ; 
    break ; 
  case 1:
    fBigBoxY = value ; 
    break ; 
  case 2:
    fBigBoxZ = value ; 
    break ; 
 }

}

//____________________________________________________________________________
Double_t AliPHOSv4::SigmaE(Double_t energy)
{
  // Calculates the energy dependent energy resolution
  
  Double_t rv = -1 ; 
  
  rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2) 
	       + TMath::Power(fResPara2/TMath::Sqrt(energy), 2) 
	       + TMath::Power(fResPara3, 2) ) ;  

  return rv * energy ; 
}

//____________________________________________________________________________
Double_t AliPHOSv4::SigmaP(Double_t energy, Int_t incidence)
{
  // Calculates the energy dependent position resolution 

  Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ; 
  Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ; 

  return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1   ; // in cm  
}

//____________________________________________________________________________
void AliPHOSv4::StepManager(void)
{
  // Only verifies if the particle reaches PHOS and stops the tracking 
  
  Int_t primary =  gAlice->GetPrimary( gAlice->CurrentTrack() ); 
  TLorentzVector lv ; 
  gMC->TrackPosition(lv) ;
  TVector3 pos = lv.Vect() ; 
  Int_t modid  ; 
  gMC->CurrentVolID(modid);
  
  // Makes a reconstructed particle from the primary particle

  TClonesArray * particlelist = gAlice->Particles() ;
  TParticle * part = (TParticle *)particlelist->At(primary) ;  

  AliPHOSFastRecParticle rp(*part) ;
  rp.SetPrimary(primary) ; 

  // Adds the response of PHOS to the particle

  MakeRecParticle(modid, pos, rp) ;
  
  // add the primary particle to the FastRecParticles list
  
  AddRecParticle(rp) ;

  // stop the track as soon PHOS is reached
  
  gMC->StopTrack() ; 

}
Commit	Line	Data
5f20d3fb	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15
	16	/* $Id$ */
	17
	18	//_________________________________________________________________________
	19	// Implementation of the PHOS manager class for fast simulations
	20	// Tracks particles until the reach a grossly designed PHOS module
	21	// Modify the particles property (momentum, energy, type) according to
	22	// the PHOS response function. The result is called a virtual reconstructed
	23	// particle.
	24	//
	25	//*-- Author: Yves Schutz (SUBATECH)
	26
	27	// --- ROOT system ---
	28
	29	#include "TBRIK.h"
	30	#include "TNode.h"
	31	#include "TParticle.h"
	32
	33	// --- Standard library ---
	34
	35	#include <stdio.h>
	36
	37	// --- AliRoot header files ---
	38
	39	#include "AliPHOSv4.h"
	40	#include "AliRun.h"
	41	#include "AliConst.h"
	42
	43	ClassImp(AliPHOSv4)
	44
5f20d3fb	45	//____________________________________________________________________________
	46	AliPHOSv4::AliPHOSv4(const char name, const char title):
	47	AliPHOS(name,title)
	48	{
	49	// ctor
	50
	51	// gets an instance of the geometry parameters class
	52
	53	fGeom = AliPHOSGeometry::GetInstance(title, "") ;
	54
	55	if (fGeom->IsInitialized() )
88bdfa12	56	cout << "AliPHOS" << Version() << " : PHOS geometry intialized for " << fGeom->GetName() << endl ;
5f20d3fb	57	else
88bdfa12	58	cout << "AliPHOS" << Version() << " : PHOS geometry initialization failed !" << endl ;
5f20d3fb	59
	60	SetBigBox(0, fGeom->GetOuterBoxSize(0) ) ;
	61	SetBigBox(1, fGeom->GetOuterBoxSize(1) + fGeom->GetPPSDBoxSize(1) ) ;
	62	SetBigBox(2, fGeom->GetOuterBoxSize(0) );
	63
	64	fNRecParticles = 0 ;
	65	fFastRecParticles = new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100) ;
	66
	67	fResPara1 = 0.030 ; // GeV
	68	fResPara2 = 0.00003 ;
	69	fResPara3 = 0.00001 ;
	70
	71	fPosParaA0 = 2.87 ; // mm
	72	fPosParaA1 = -0.0975 ;
	73	fPosParaB0 = 0.257 ;
	74	fPosParaB1 = 0.137 ;
	75	fPosParaB2 = 0.00619 ;
	76	}
	77
	78	//____________________________________________________________________________
	79	AliPHOSv4::~AliPHOSv4()
	80	{
	81	// dtor
	82
	83	fFastRecParticles->Delete() ;
	84	delete fFastRecParticles ;
	85	fFastRecParticles = 0 ;
	86
	87	}
	88
	89	//____________________________________________________________________________
	90	void AliPHOSv4::AddRecParticle(const AliPHOSFastRecParticle & rp)
	91	{
	92	// Add a virtually reconstructed particle to the list
	93
	94	new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
	95	fNRecParticles++ ;
	96	}
	97
	98	//____________________________________________________________________________
	99	void AliPHOSv4::BuildGeometry()
	100	{
	101	// Build the PHOS geometry for the ROOT display
	102	//BEGIN_HTML
	103	/*
	104	<H2>
	105	PHOS FAST in ALICE displayed by root
	106	</H2>
	107	<H4> All Views </H4>
	108	<P>
	109	<CENTER>
	110	<IMG Align=BOTTOM ALT="Fast All Views" SRC="../images/AliPHOSv4AllViews.gif">
	111	</CENTER></P>
	112	<H4> Front View </H4>
	113	<P>
	114	<CENTER>
	115	<IMG Align=BOTTOM ALT="Fast Front View" SRC="../images/AliPHOSv4FrontView.gif">
	116	</CENTER></P>
	117	*/
	118	//END_HTML
	119
	120	const Int_t kColorPHOS = kRed ;
	121
	122	Double_t const kRADDEG = 180.0 / kPI ;
123
124	new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2,
125	GetBigBox(1)/2,
126	GetBigBox(2)/2 );
127
128	// position PHOS into ALICE
129
130	Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
131	Int_t number = 988 ;
132	Float_t pphi = TMath::ATan( GetBigBox(0) / ( 2.0 * fGeom->GetIPtoCrystalSurface() ) ) ;
133	pphi *= kRADDEG ;
134	TNode * top = gAlice->GetGeometry()->GetNode("alice") ;
135
136	char * nodename = new char[20] ;
137	char * rotname = new char[20] ;
138
139	for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
140	Float_t angle = pphi * 2 * ( i - fGeom->GetNModules() / 2.0 - 0.5 ) ;
141	sprintf(rotname, "%s%d", "rot", number++) ;
142	new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0);
143	top->cd();
144	sprintf(nodename,"%s%d", "Module", i) ;
145	Float_t x = r * TMath::Sin( angle / kRADDEG ) ;
146	Float_t y = -r * TMath::Cos( angle / kRADDEG ) ;
147	TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ;
148	bigboxnode->SetLineColor(kColorPHOS) ;
149	fNodes->Add(bigboxnode) ;
150	}
151	delete[] nodename ;
152	delete[] rotname ;
153	}
154
155	//____________________________________________________________________________
156	void AliPHOSv4::CreateGeometry()
157	{
158	// Create the geometry for GEANT
159
160	AliPHOSv4 phostmp = (AliPHOSv4)gAlice->GetModule("PHOS") ;
161
162	if ( phostmp == NULL ) {
163
164	fprintf(stderr, "PHOS detector not found!\n") ;
165	return ;
166
167	}
168
169	// Get pointer to the array containing media indeces
170	Int_t *idtmed = fIdtmed->GetArray() - 699 ;
171
172	Float_t bigbox[3] ;
173	bigbox[0] = GetBigBox(0) / 2.0 ;
174	bigbox[1] = GetBigBox(1) / 2.0 ;
175	bigbox[2] = GetBigBox(2) / 2.0 ;
176
177	gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
178
179	// --- Position PHOS mdules in ALICE setup ---
180
181	Int_t idrotm[99] ;
182	Double_t const kRADDEG = 180.0 / kPI ;
183
184	for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
185
186	Float_t angle = fGeom->GetPHOSAngle(i) ;
187	AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
188
189	Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
190
191	Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
192	Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
193	gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
194
195	} // for GetNModules
196
197	}
198
199
200	//____________________________________________________________________________
201	void AliPHOSv4::Init(void)
202	{
203	// Prints out an information message
204
205	Int_t i;
206
207	printf("\n");
208	for(i=0;i<35;i++) printf("*");
209	printf(" FAST PHOS_INIT ");
210	for(i=0;i<35;i++) printf("*");
211	printf("\n");
212
213	// Here the PHOS initialisation code (if any!)
214
215	for(i=0;i<80;i++) printf("*");
216	printf("\n");
217
218	}
219
220	//___________________________________________________________________________
221	Float_t AliPHOSv4::GetBigBox(Int_t index)
222	{
223	// Get the X, Y or Z dimension of the box describing a PHOS module
224
225	Float_t rv = 0 ;
226
227	switch (index) {
228	case 0:
229	rv = fBigBoxX ;
230	break ;
231	case 1:
232	rv = fBigBoxY ;
233	break ;
234	case 2:
235	rv = fBigBoxZ ;
236	break ;
237	}
238	return rv ;
239	}
240
241	//___________________________________________________________________________
242	void AliPHOSv4::MakeBranch(Option_t* opt)
243	{
244	// Create new branch in the current reconstructed Root Tree
245
246	AliDetector::MakeBranch(opt) ;
247
248	char branchname[10];
249	sprintf(branchname,"%s",GetName());
250	char *cd = strstr(opt,"R");
251
252	if (fFastRecParticles && gAlice->TreeR() && cd) {
253	gAlice->TreeR()->Branch(branchname, &fFastRecParticles, fBufferSize);
254	}
255	}
256
257	//____________________________________________________________________________
258	Double_t AliPHOSv4::MakeEnergy(const Double_t energy)
259	{
260	// Smears the energy according to the energy dependent energy resolution.
261	// A gaussian distribution is assumed
262
263	Double_t sigma = SigmaE(energy) ;
264	return fRan.Gaus(energy, sigma) ;
265	}
266
267	//____________________________________________________________________________
268	TVector3 AliPHOSv4::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const Double_t phi)
269	{
270	// Smears the impact position according to the energy dependent position resolution
271	// A gaussian position distribution is assumed
272
273	TVector3 newpos ;
274	Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
275	Double_t x = fRan.Gaus( pos.X(), sigma ) ;
276	sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
277	Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
278	Double_t y = pos.Y() ;
279
280	newpos.SetX(x) ;
281	newpos.SetY(y) ;
282	newpos.SetZ(z) ;
283
284	return newpos ;
285	}
286
287	//____________________________________________________________________________
288	void AliPHOSv4::MakeRecParticle(const Int_t modid, const TVector3 pos, AliPHOSFastRecParticle & rp)
289	{
290	// Modify the primary particle properties according
291	// 1. the response function of PHOS
292	// 2. the performance of the EMC+PPSD setup
293
294	Int_t type = MakeType( rp ) ;
295	rp.SetType(type) ;
296
297
298	// get the detected energy
299
300	TLorentzVector momentum ;
301	rp.Momentum(momentum) ;
302	Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ;
303	Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
304	Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)
305	+ TMath::Power( rp.GetMass(), 2) ) ;
306
307	// get the angle of incidence
308
309	Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ;
310	Double_t incidencephi = ( 270 + fGeom->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;
311
312	// get the detected direction
313
314	TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ;
315	modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ;
316
317	// Set the modified 4-momentum of the reconstructed particle
318
319	rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ;
320
321	}
322
323	//____________________________________________________________________________
324	Int_t AliPHOSv4::MakeType(AliPHOSFastRecParticle & rp )
325	{
326	// Generate a particle type using the performance of the EMC+PPSD setup
327
328	Int_t rv = AliPHOSFastRecParticle::kUNDEFINED ;
329	Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
330	Int_t test ;
331	Float_t ran ;
332	if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) )
333	test = - 1 ;
334	else
335	test = rp.GetPdgCode() ;
336
337	switch (test) {
338
339	case 22: // it's a photon
340	ran = fRan.Rndm() ;
341	if ( ran <= 0.5 ) // 50 %
342	rv = AliPHOSFastRecParticle::kGAMMA ;
343	else {
344	ran = fRan.Rndm() ;
345	if( ran <= 0.9498 )
346	rv = AliPHOSFastRecParticle::kNEUTRALEM ;
347	else
348	rv = AliPHOSFastRecParticle::kNEUTRALHA ;
349	}
350	break ;
351
352	case 2112: // it's a neutron
353	ran = fRan.Rndm() ;
354	if ( ran <= 0.9998 )
355	rv = AliPHOSFastRecParticle::kNEUTRALHA ;
356	else
357	rv = AliPHOSFastRecParticle::kNEUTRALEM ;
358	break ;
359
360	case -2112: // it's a anti-neutron
361	ran = fRan.Rndm() ;
362	if ( ran <= 0.9984 )
363	rv = AliPHOSFastRecParticle::kNEUTRALHA ;
364	else
365	rv = AliPHOSFastRecParticle::kNEUTRALEM ;
366	break ;
367
368	case 11: // it's a electron
369	ran = fRan.Rndm() ;
370	if ( ran <= 0.9996 )
371	rv = AliPHOSFastRecParticle::kELECTRON ;
372	else
373	rv = AliPHOSFastRecParticle::kCHARGEDHA ;
374	break;
375
376	case -11: // it's a positon
377	ran = fRan.Rndm() ;
378	if ( ran <= 0.9996 )
379	rv = AliPHOSFastRecParticle::kELECTRON ;
380	else
381	rv = AliPHOSFastRecParticle::kCHARGEDHA ;
382	break;
383
384	case -1: // it's a charged
385	ran = fRan.Rndm() ;
386	if ( ran <= 0.9996 )
387	rv = AliPHOSFastRecParticle::kCHARGEDHA ;
388	else
389	rv = AliPHOSFastRecParticle::kGAMMA ;
390
391	break ;
392	}
393
394
395	return rv ;
396	}
397
398	//___________________________________________________________________________
399	void AliPHOSv4::ResetPoints()
400	{
401	// This overloads the method in AliDetector
402
403	ResetFastRecParticles() ;
404	}
405
406	//___________________________________________________________________________
407	void AliPHOSv4::ResetFastRecParticles()
408	{
409	// Resets the list of virtual reconstructed particles
410
411	if (fFastRecParticles)
412	fFastRecParticles->Clear() ;
413	fNRecParticles = 0 ;
414	}
415
416	//___________________________________________________________________________
417	void AliPHOSv4::SetBigBox(Int_t index, Float_t value)
418	{
419	// Set the size of the Box describing a PHOS module
420
421	switch (index) {
422	case 0:
423	fBigBoxX = value ;
424	break ;
425	case 1:
426	fBigBoxY = value ;
427	break ;
428	case 2:
429	fBigBoxZ = value ;
430	break ;
431	}
432
433	}
434
435	//____________________________________________________________________________
436	Double_t AliPHOSv4::SigmaE(Double_t energy)
437	{
438	// Calculates the energy dependent energy resolution
439
440	Double_t rv = -1 ;
441
442	rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2)
443	+ TMath::Power(fResPara2/TMath::Sqrt(energy), 2)
444	+ TMath::Power(fResPara3, 2) ) ;
445
446	return rv * energy ;
447	}
448
449	//____________________________________________________________________________
450	Double_t AliPHOSv4::SigmaP(Double_t energy, Int_t incidence)
451	{
452	// Calculates the energy dependent position resolution
453
454	Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ;
455	Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ;
456
457	return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm
458	}
459
460	//____________________________________________________________________________
461	void AliPHOSv4::StepManager(void)
462	{
463	// Only verifies if the particle reaches PHOS and stops the tracking
464
465	Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
466	TLorentzVector lv ;
467	gMC->TrackPosition(lv) ;
468	TVector3 pos = lv.Vect() ;
469	Int_t modid ;
470	gMC->CurrentVolID(modid);
471
472	// Makes a reconstructed particle from the primary particle
473
474	TClonesArray * particlelist = gAlice->Particles() ;
475	TParticle * part = (TParticle *)particlelist->At(primary) ;
476
477	AliPHOSFastRecParticle rp(*part) ;
478	rp.SetPrimary(primary) ;
479
480	// Adds the response of PHOS to the particle
481
482	MakeRecParticle(modid, pos, rp) ;
483
484	// add the primary particle to the FastRecParticles list
485
486	AddRecParticle(rp) ;
487
488	// stop the track as soon PHOS is reached
489
490	gMC->StopTrack() ;
491
492	}
493